The present invention relates generally to cordless telephone systems which are connected to a switched telephone network and, in particular, to registration of a new cordless telephone to an existing cordless telephone system.
Cordless telephone systems comprise an access unit which is connected through a subscriber loop to a switched telephone network and a plurality of cordless telephones. A two-way radio channel is established between the access unit and each cordless telephone by transmitting the system identification number of the system from a transmit end and verifying at a receive end that the transmitted system identification number is identical to that of the own system. This verification operation is necessary to avoid interference which might occur between cordless telephone systems which cover adjacent service areas. A system identification number is assigned to each system at the shipment from the factory by storing such number into the read-only memory of the access unit and into the read-only memory of each of the associated cordless telephones. When a new cordless telephone is to be added to an existing system, the new telephone must be provided with a read-only memory in which the same system identification number is stored. Such read-only memories are currently prepared by the manufacturer in advance for future system expansion or prepared by a servicing company on a per demand basis. This adds to the total manufacturing cost of the system.